Process for the production of secondary alkylaryl hydrocarbons



United States Patent M PROCESS FOR THE PRODUCTION OF SECONDARY ALKYLARYL HYDROCARBONS George L. Hervert, Downers Grove, 11]., assignor to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware No Drawing. Application May 26, 1951, Serial No. 228,538

7 Claims. (Cl. 260-671) This invention relates to a process for the production of alkylaryl hydrocarbons having a particular molecular structure which is especially suitable for the manufacture of the corresponding sulfonic acids and their salts as surface active agents and particularly detergents and wetting agents. More specifically, this invention concerns a method of producing the highly desirable alkylaryl hydrocarbons and their sulfonic acid derivatives and sulfonate salts in which the alkyl group is a long chain hydrocarbon radical attached to the aryl nucleus through a secondary carbon atom.

A large number of specific compounds characterized as alkylaryl sulfonic acids and their substantially neutral alkali metal and organic amine salts are known to have excellent detersive properties in aqueous solution and are outstanding for this purpose in that they are effective in so-called hard water without formation of insoluble calcium and/or magnesium salt derivatives when added to such hard water, the latter tendency being one of the typical characteristic properties of fatty acid soaps which form the familiar and disagreeable curd when added to hard water. The present invention provides a series of compounds broadly characterized as alkylaryl sulfonic acids and sulfonates, which are characterized more specifically as having a particular structure in which the alkyl group is attached to the aryl nucleus through a secondary carbon atom of the alkyl chain. These compounds have all of the desirable properties of the alkylaryl sulfonate detergents heretofore known in that they likewise do not form insoluble curd when added to hard water, but, in addition, are particularly effective and active detergents which may be prepared by a commercially and economiinvention is to provide a process for the manufacture of alkylaryl sulfonate detergents by an economical process in commercially attractive yields.

In one of its embodiments the present invention concerns a process for the production of an alkylaryl hydrocarbon in which the alkyl group is joined to the aryl nucleus through a secondary carbon atom of the alkyl group which comprises reacting an alkyl halide containing from about 7 to about 16 carbon atoms per molecule with ethylene to form a primary alkyl halide containing from about 9 to about 18 carbon atoms per molecule, and condensing said primary alkyl halide with an aromatic hydrocarbon containing a nuclearly displaceable hydrogen atom to form an alkyl aryl hydrocarbon in which the alkyl group is attached to the aryl nucleus through a secondary carbon atom of said alkyl group.

2,771,496 Patented Nov. 20, 1956 Another embodiment of the invention relates to a process for the production of an alkylaryl sulfonate surface active agent which comprises reacting a propylene polymer containing from about 9 to about 12 carbon atoms per molecule with anhydrous hydrogen chloride to form an alkyl halide of the chain length corresponding to the propylene polymer, condensing said alkyl halide with ethylene at a superatmospheric pressure and in the presence of a Friedel-Crafts metal halide catalyst to form a primary alkyl halide, condensing said alkyl halide with an aryl hydrocarbon containing a nuclearly replaceable hydrogen atom in the presence of an acid-acting catalyst at a temperature of from about 0 to about 120 C. to form an alkylaryl hydrocarbon containing from about 11 to about 14 carbon atoms per alkyl group in which the alkyl group is attached to the aryl nucleus through a secondary carbon atom and thereafter sulfonating said alkylaryl hydrocarbon.

Other objects and embodiments of the invention relating to specific reactants, specific methods of conducting the separate stages of the present process and further specifications with respect to the products of this invention will be referred to in greater detail in the following description.

The method of preparing surface active agents by the sulfonation of a particular class of. alkylaryl hydrocarbons having a specific structure is applicable with particular advantage to benzenoid hydrocarbons, that is, aromatic hydrocarbons containing a substitutable phenyl nucleus having not more than about 3 alkyl groups as nuclear substituents. Especially desirable detergents have been prepared from alkyl benzenes containing not more than 2 nuclear short chain alkyl groups, and not more than 1 nuclear long chain alkyl group containing from about 9 to about 18 carbon atoms per long chain alkyl group. In order to form surface active agents having the requisite balance of the hydrophilic and hydrophobic groups present in the structure of the molecule of surface active agent, the short chain alkyl group or groups desirably contain not more than 2 carbon atoms per group, the preferred detergent products provided herein containing either no short chain nuclear alkyl group or not more than one of such groups which if present is preferably a methyl radical. Thus, of the benzenoid hydrocarbon charging stock utilizable in the present process, selected from the group consisting of benzene, toluene, Xylene, methylethylbenzene and diethylbenzene, benzene and toluene are preferred for the preparation of the most effective surface active agents and detergents. The process provided herein may also be utilized for the preparation of alkylaryl hydrocarbon sulfonates containing a polycyclic aryl nucleus .with substantially like results as to yield and structure of product, although process conditions and reactants suitable for the preparation of effective surface active agents therefrom may require modification for the polycyclic aryl hydrocarbon starting materials. When utilized, typical exemplary charging stock of the latter polycyclic aromatic hydrocarbons utilizable in the process include, for example, the alkylated phenanthrene, naphthalene, diphenyl, anthracene and other polycyclic aryl hydrocarbons, the mono-alkylated derivatives having alkyl groups containing from about 5 to about 18 the alkyl group contains from about 5 to about 9 carbon atoms per group from which particularly desirable detergent products may be prepared.

As heretofore indicated, the present invention is concerned with the production of said alkylaryl hydrocarbons from which the sulfonic acid and sulfonate salt deriva-,

tives may be prepared in which compounds the long chain alkyl group is attached to the aryl nucleus through a secondary carbon atom of the alkyl group. These products having the specific structure designated as dis- .inguished from the alkylaryl sulfonates of the prior art which contain an alkyl group occupying a random position on the aryl nucleus, form particularly effective surface active agents, having the capacity to remove foreign matter from soiled articles in substantially shorter time and more completely than products in which the alkyl group occupies a different structural relationship to the aryl nucleus. The sulfonic acids as well as the sulfonate salts of the present products tend to be more soluble in water at lower temperatures and may be dissolved in substantially greater quantities in a given volume of water than the alkylaryl sulfonate products heretofore prepared containing a random attachment of the alkyl group to the aryl nucleus.

The alkylating agent utilized in preparation of the alkylaryl hydrocarbons are referred to herein as primary alkyl halides formed by the condensation of ethylene with an alkyl halide of shorter chain length. Since desirable surface active agents of the present series contain an alkyl group having from about 9 to about 18 carbon atoms per group, as established in a series of tests to determine the detersive properties of the homologs in this series, the alkyl halide condensed with ethylene to form the primary alkyl halide must of necessity contain from about 7 to about 16 carbon atoms per molecule. One of the preferred methods for the preparation of the initial alkyl halide starting material utilized in the formation of the primary alkyl halide alkylating agent involves the condensation of an olefinic hydrocarbon (one of the most convenient and available sources of starting material) with a hydrogen halide.

One of the preferred sources of olefinic-hydrocarbons utilizable in the preparation of the initial alkyl halide are the products formed by the polymerization of a lower molecular Weight olefin containing from about 3 to about 6 carbon atoms per molecule, including such olefins as propylene and butylene or mixtures thereof as the preferred monomers. Although propylene polymers are generally preferred in the preparation of the present initial halides because of their desirable chain structure in that they form alkylates containing alkyl substituents capable of resisting depolymerization when contacted with strongly acidic reagents, such as the sulfonating agent utilized in the preparation of the sulfonic acids herein contemplated, mixed polymers of propylene with butylene or polymers of the various butylenes as well as amylene and hexylene polymers also produce desirable alkyl halides for preparation of the present products.

Other desirable olefinic hydrocarbons useful for the preparation of the initial alkyl halide by reaction with the hydrogen halide reactant includes certain thermally cracked petroleum fractions which boil at temperatures corresponding to the desired olefins containing from about 7 to about 16 carbon atoms per molecule. In case of both of the above sources of olefins, that is the olefin polymers and the fractions separated from thermally cracked petroleum products, the fractions desirable for preparation of the present detergent products boil at temperatures of from about 95 to about 350 C.

The alkyl halides are formed from the indicated olefinic hydrocarbons by condensing the olefin with a hydrogen halide such as hydrogen chloride, hydrogen bromide or hydrogen iodide, preferably with hydrogen chloride which forms the corresponding alkyl chloride, considered as one of the most economical alkyl halide starting materials. The alkyl halides formed in this manner are produced in large, almost quantitative yields by merely contacting the olefin with the hydrogen halide at temperatures of from 70 to about 150 C., preferably at temperatures of from about 20 to 100 C., the hydrogen and halogen atoms becoming attached to the doubly bonded carbon atoms of the olefin reactant. Superatmospheric pres.-

sures or catalysts as acetic acid are generally desirable to enhance the formation of the alkyl halides, although not essential to the successful formation of the mono-halogen substituted product. Contact material such as quartz chips, berl saddles, kieselguhr, preferably particles of relatively high porosity may be used to pack the reactor to enhance contact between the gaseous and liquid phases. A suitable reactor for this reaction may comprise, for example, a tubular reactor packed with the contact material over which the olefin in liquid phase is allowed to flow in countercurrent relationship to the hydrogen halide which is allowed to percolate upwardly through the contact material and liquid olefinic hydrocarbon. Although not essential to completion of the reaction, the reactor is desirably maintained at a superatmospheric pressure which increases the rate of addition of the hydrogen halide to the olefinic hydrocarbon. The product may thereafter be fractionally distilled to separate a particularly desired fraction, such as the C7 to C16 fraction, or more desirably, the C10 to C1 fraction from the remaining products and unreacted olefins, if any. Another source of the initial alkyl halides utilizable in the reaction are the products formed by subjecting a C1 to C16 paraifinic hydrocarbon fraction such as a kerosene distillate to halogenation under such conditions as to form the mono-halogen-substituted alkyl halides. The preparation of alkyl halides and their purification is represented by well known processes in the art and further details of their preparation may be obtained by reference to such art.

The intermediate reactants in the present process, re ferred to as primary alkyl halides are prepared by the specific method provided herein to produce a compound which when reacted with an aryl hydrocarbon containing a nuclearly replaceable hydrogen atom are condensed therewith to form a carbon-to-carbon bond between the secondary carbon atom of the alkyl group and a nuclear carbon atom of the aryl hydrocarbon ring, forming the secondary alkylaryl hydrocarbon intermediate product desired as charging stock to the sulfonation reaction in which the present su'lfonate detergents and surface active agents are prepared. The following series of equations represents the present process for the production of the alkylaryl hydrocarbon intermediate, the equations representing the individual reactions as they are believed to occur: A) If: 1'12 Iti 1'12 (1) RC=O-R BK RGC-R Initial Olefin Hydrogen Initial alkyl halide containing from halide, about; 7 to about H01, HB, 16 carbon atoms or HI per molecule fil Ill; R1 R2 (2) RC[ (lJ-R 1220:0112 R-C-C-R z-C-X Primary alkyl halide 1'11 lit: T112 (3) RCC-R Art! UK R-(i}-CR H (13H; H H O-X H-CAr Aromatic hydrocarbon 1130 wherein R, R, R1 and R2 are substituents selected from the group consisting of hydrogen and alkyl and further characterized in that the total number of carbon atoms in R and/or R is equal to from about 7 to about 16.

The primary alkyl halides formed in the reaction represented by Equation 2 above are prepared by reacting ethylene with the initial alkyl halide formed by hydrohalogcnation of an olefin or halogenation of a paraffin at amen a temperature of from about -70 to 100 C., and preferably at temperatures of from about to about. 50 C., and preferably in the presence of: anacid-acting'condensation catalyst such as a mineral. acid, a Friedel-Crafts metal halide, boron trifluoride or boron trichloride and at a superatmospheric pressure. The primary alkyl halide may be formed, for example, by merely bubbling the gaseous ethylene into the initial alkyl halide which is a liquid at the above reaction temperatures or by pressurizing the ethylene into a stirred reactor operated at superatmospheric pressures while the gaseous phases therein are brought into intimate contact by stirring or other means of agitation. Suitable catalysts for the reaction are selected from the general group referred to as the acid-acting inorganic substances, such as the Friedel- Crafts metal halides heretofore referred to, including anhydrous aluminum chloride and aluminum bromide, ferric chloride, zinc chloride, zirconium chloride, bismuth chloride, nickel chloride, stannic chloride or the bromide salts of the corresponding metals, and others generally recognized as such in the art. The addition complexes of the above acid-acting compounds containing one or more molecules of an organic oxygen-containing compound, such as the dialkyl ethers, the low molecular Weight alcohols, the esters, nitroparaflins, etc., are also suitable catalysts for promoting the condensation of ethylene with the initial alkyl halide reactant. Another group of catalysts which promote the condensation reaction are boron trichloride and boron trifluoride or the addition complexes thereof with the above oxygen-containing compounds, typical addition complexes being the boron trifluoride monoethyl etherate, the boron trifluoride monoethanolate etc. The product containing the primary alkyl halide formed in the above condensation reaction is thereafter separated from the catalyst and may be fractionally distilled to recover a particular fraction more suitable for detergent production than the entire product of the condensation reaction.

The condensation of the primary alkyl halide with the aromatic hydrocarbon charging stock, hereinabove specified, may be effected in accordance with procedures well recognized in the chemical arts. Although the reaction is generally operable in a non-catalyzed system at relatively higher temperatures than a catalyzed reaction system and at superatmospheric pressures, it is preferable, in order to obtain maximum yields and eliminate oracle ing and isomerization side reactions, to react the aromatic hydrocarbon and primary alkyl halide in the presence of a catalyst characterized as an acid-acting compound of the type heretofore described, and in addition, including certain mineral acids such as substantially anhydrous hydrogen fluoride, concentrated sulfuric acid and other inorganic acids. One of the preferred catalysts for the reaction is an aluminum halide selected from aluminum chloride and aluminum bromide. The amount of catalyst utilized in the reaction may be varied within relatively broad limits, generally from about to about 25 parts of catalyst per 100 parts by Weight of alkyl halide charged to the reaction, and preferably from about 8 to about parts of catalyst per 100 parts by weight of the primary alkyl halide. The above proportions, are particularly applicable to reaction systems in which the anhydrous aluminum halides are employed, and where other catalysts are preferred, the proportion of catalyst to alkyl halide reactant may vary depending particularly upon the concentration of the active component in the catalyst. The proportion of alkyl halide to aromatic hydrocarbon reactant is also a reaction variable of considerable importance for obtaining the monoalkyl product desirable for detergent manufacture. Although equimolecular proportions of the aromatic hydrocarbon and primary alkyl halide reactants are theoretically sufficient to produce the monoalkyl product, it is generally preferred to maintain the proportion of reactants in the reaction vessel at a greater than 1 to 1 proportion, preferably separated for recycle to the condensation reaction.

from about 1.25 to about 10 to 1 moles of aromatic hydro carbon per mole of primary alkyl halide, thereby reducing the tendency to form undesirable polyalkyl substituted aromatic hydrocarbon alkylates and concurrently increasing the yield of desired mono-alkylates. The condensation reaction is effected at a temperature of from about -30 to about 120 C., preferably at temperatures of from about 0 to' about C. and at superatmospheric pressures sufficient to maintain the catalyst and reactants in substantially liquid phase.

The reactants and catalyst may be contacted in any suitable manner, but in a preferred procedure, the catalyst, such as aluminum chloride, is dissolved in one of the reactants or in an inert solvent, such as a parafiinic hydrocarbon, chloroform, carbon tetrachloride, etc. and the resulting solution thereafter thoroughly mixed at the desired reaction temperature with the reactants. One of the preferred procedures for reacting toluene or a higher homolog of a benzenoid hydrocarbon containing multiple substituents with the primary alkyl halide, comprises dissolving the catalyst in the aromatic hydrocarbon and subsequently mixing the resulting solution with the alkyl halide in the desired proportions and at the desired re action temperature.

Following completion of the condensation reaction, the catalyst phase, generally a dark-colored sludge, is separated by decantation from the upper layer hydrocarbon product, the latter is washed with water or an aqueous Washing agent, and thereafter dried and fractionally distilled, preferably at said atmospheric pressures, to separate one or more fractions suitable for detergent manufacture. Lower boiling fractions corresponding to the alkyl halide and/or aromatic hydrocarbon, if any remains unreacted in the product, may be In the case of benzene and toluene alkylates, the fractions in which the constituent alkylaryl hydrocarbons contain long chain alkyl groups having from 9 to about 18 carbon atoms per group boil at atmospheric pressures from about 260 to about 350 C., some of the isomers boiling at temperatures as high as 400 C.

The sulfonationof the alkylaryl hydrocarbon formed in the proceeding-condensation reaction may be effected by reaction with any suitable sulfonating agent, such as concentrated sulfuric acid containing at least 98.5%

acid, the oleums containing free sulfur triox-ide, up to about 65% free sulfur trioxide, sulfur trioxide itself in its various forms, particularly the gamma form which remains liquid at the usual sulfonating temperatures, chlorosulfonic acid, and others selected generally from the highly concentrated reagents. Sulfonation of the alkylaryl hydrocarbon to produce a substantially quantitative yield of the corresponding sulfonic acid may be obtained at temperatures of from about 0 to about .C. and when utilizing the generally more active sulfonating agents, such as a sulfuric acid oleum or sulfur.

trioxide, the reaction temperature is preferably maintained at a somewhat lower level, from about 0 to about 50 C. The proportion of sulfonating agent to alkylaryl hydrocarbon reactant in the sulfonation reaction is also variable, depending upon the activity of the sulfonating agent. in general, substantially complete sulfonation may be obtained with sulfuric acid of 98.5 to 100% concentration utilizing from about 5 to about 9 moles of acid per mole of alkylate. As the strength of the acid is increased to oleums containing free sulfur trioxide, the proportion of sulfonating agent required in the reaction mixture is correspondingly decreased. in the case of a 65 oleum the proportion of acid to alkylate is from about 1.3 to about 2.5 moles of total sulfur trioxide (that is, free and combined in the form of sulfuric acid). Utilizing sulfur trioxide alone as a sulfonating agent substantially quantitative sulfonation of the alkylate to the corresponding alkylaryl sulfonic acid 7 may be effected in the presence of from about 1 to about 1.4 moles of sulfur trioxide per mole of alkylate.

In order to control the formation of colored materials during the sulfonation reaction and the presence of undesirable oxidation and cracking reaction products in the final detergent product, the presence of which detracts from the appearance and detersive efiiciency of the alkylaryl sulfonic acids and their sulfonate salts, the sulfonation is desirably conducted in the presence of an inert solvent which preferably boils at a temperature within the desired range of sulfonation temperatures. By selecting the inert solvent on the basis of the boiling point corresponding to the sulfonation temperature, a diluent-refrigerant is provided for the reaction mixture which maintains the reaction temperature within the predetermined limits. The diluent is also preferably selected on the basis of reducing the viscosity of the reaction mixture in order to permit rapid dissipation of the sulfonating agent in the reaction mixture, therefore avoiding the development of local zones of high temperature as a result of the highly exothermic sulfonation reaction. The diluent also tends to reduce disulfonation of the alkylate, the sulfonates of which are less desirable as detergents than the mono-sulfonate. Suitable inert solvents or diluent-refrigerants include such compounds as the low molecular weight paraffinic hydrocarbons, such as butane, pentane, and hexane, the chloroalkanes, such as carbon tetrachloride, mono-, chloroethane, dichloroethane, dichlorodifiuorornethane, ethylene dichloride and others, the fiuorocarbons such as perfluoropropane, perfiuorobutane, etc. The solvent may be allowed to remain in the reaction mixture following completion of the sulfonation reaction and thereby utilized to control the reaction temperatures developed in the subsequent stages of the process.

The alkylaryl sulfonic acid intermediate product in the production of the substantially neutral sulfonate salts thereof is desirably separated from the excess sulfonating agent present in the sulfonation reaction mixture in order to reduce the quantity of neutralizing agent required to form the corresponding sulfonate salts. The excess sulfonating agent is preferably separated from the intermediate sulfonic acids prior to neutralization, since the sulfate salts of the neutralizing agent when utilized as a builder salt in compositions with the detergent sulfonate may be purchased on the market at less expense than when formed by neutralizing the excess sulfonating agent with the relatively more expensive caustic. The sulfonic acids may be separated by the addition of water to the sulfonation reaction mixture until phase separation occurs at which point the lower, dilute, sulfuric acid phase will contain from about 80 to about 90% sulfuric acid. The process, known generally as springing is also accompanied by the liberation of large amounts of heat. It is therefore desirable to control the temperature of the mixture during dilution to prevent discoloration of the final detergent product by permitting the diluentrefrigerant to evaporate from the mixture, as for example, when originally added to the sulfonation reaction and retained therein for subsequent stages of the process.

The preferred form of the present detergent product is the substantially neutral alkyl aromatic sulfonate salts formed by neutralization of the separated sulfonic acids with a suitable basic reagent capable of forming a watersoluble salt when neutralized to a pH of approximately 7. The salts are prepared by reacting the sulfonic acid with a basic reagent in any suitable form, such as the oxide, hydroxide, carbonate or as the salts of a weak acid capable of being replaced by the sulfonic acid. The bases may include the alkali metal, the alkaline earth metal oxides, hydroxides or carbonates, ammonia, the organic amines, such as the mono and polyalkyl amines, the alkanolamines such as the mono-, di-, and triethanol amines, the polyalkylene amines, etc. Since neutralization is also highly exothermic which in the absence of temperature control may cause the development of undesirable colored products in the final detergent, the neutralization is also desirably conducted in the presence of a diluent-refrigerant of the class hereinabove specified.

The present invention is illustrated with respect to specific embodiments thereof as to reactants, catalysts, and reaction conditions in the following examples which, however, are intended merely for illustrative purposes and not to limit the scope of the invention in strict accordance therewith.

Example I A mixture of alkyl chlorides, a major proportion of which are components containing about 12 carbon atoms per molecule and comprising the initial alkyl halide rcactant condensable with ethylene to form a primary allcyl halide as specified herein, may be prepared by the reaction of an olefinic hydrocarbon containing a corresponding number of carbon atoms with hydrogen chloride at condensation reaction conditions. In the following preparation, a propylene tetramer fraction boiling from about 180 to about 225 C. is utilized as the source of the olefinic hydrocarbons for the preparation of the alltyl chloride. 168 grams (1 mole) of the above olefinic frac tion and about /3 of its volume of berl saddles are placed in a pressure autoclave mounted on a fulcrum such that the contents of the autoclave may be agitated by rocking the autoclave from end to end to provide efficient mixing of the autoclave contents. The autoclave is closed and pressured to approximately 100 atmospheres with dry, gaseous hydrogen chloride. The mixture is then heated to about C. for four hours as the autoclave is rocked to mix the reactants. Following the above reaction period, the liquid contents of the reactor are transferred to a distillation column and the product distilled at atmospheric pressure to recover the desired alltyl chloride. The material boiling below 205 C. (about 0.2% of the charge) is rejected and the remaining fractions collected.

The predominantly dodecylchloride product of the above hydrohalogenation reaction is converted to the primary tetradecylchloride by reaction With ethylene. The dodecylchloride is placed in a vertical tubular reactor packed with berl saddles and its condensation with ethylene is effected by bubbling the latter at a temperature of approximately 50" C. into the bottom of the packed tube at a rate sufiicient to maintain the temperature of the reaction at approximately 50 C., the ethylene being charged into the reactor through a fritted glass plate which distributes the ethylene in the liquid dodecylchloride as finely divided bubbles. The introduction of the ethylene is continued until approximately 26 to 28 grams are reacted with the dodecylchloride, following which the product is transferred to the alkylation reactor.

The primary tetradecylchloride product of the above reaction is condensed with toluene to form a sec-alkyltoluene by means of the following process. The condensation of the above prepared tetradecylchloride with toluene is effected in the presence of anhydrous hydrogen chloride gas and aluminum chloride catalyst in a reaction vessel fitted with a mechanical stirrer which uniformly distributes the catalyst throughout the liquid reactants to provide maximum interfacial contact and enhance the reaction rate. Two moles (184 grams) of toluene and one mole of tetradecylchloride (233 grams) are cooled to 20 C., placed in a rotating pressure autoclave, together with 46 grams of anhydrous aluminum chloride (about 20% by weight of the alkyl halide charged to the process) and pressured to 20 atmospheres with anhydrous hydrogen chloride. The autoclave is rotated under the above conditions to eltect mixing of the reactants while maintaining the temperature of the mixture at approximately 20" C. by externally cooling the autoclave. Following a reaction period of approximately 1.5 hours. the mixture is allowed to stand quiescent until the emulsion separates into two phases, a lower predominantly aluminum chloride sludge phase and an upper predominantly hydrocarbon phase. The two phases are decanted, the upper phase washed with water, dried, and distilled, first at atmospheric pressure to remove excess toluene therefrom, and thereafter at a pressure of about 10 mm. Hg pressure to separate the tetradecyltoluene alkylate boiling from about 320 to about 380 C.

The above alkylate is converted to the corresponding alkylaryl sulfonate detergent product by sulfonation followed by neutralization of the resulting sulfonic acid with a suitable base to form a water-soluble detergent product. One mole of the above tetradecyltoluene alkylate (288 grams) is mixed with approximately four volumes of liquid n-butane diluent maintained in liquid phase by reflux of the vaporized butane into a Dry Ice condenser and the mixture rapidly stirred as 308 grams (approximately 3.4 moles) of 30% oleum is added dropwise into the mixture over a period of approximately 1.5 hours. The mixture is stirred for an additional 0.5 hour during which the reaction temperature is maintained substantially constant at approximately C. by reflux of the vaporized butane diluent from the reaction mixture into the Dry Ice condenser.

The sulfona-tion reaction product is a homogeneous emulsion from which the excess sulfuric acid may be separated by adding water to the mixture as the latter is stirred until phase separation occurs. Water is added to the above sulfonation mixture and phase separation occurs when the resulting separated sulfuric acid phase contains approximately 20% water. The upper sulfonic acid product phase is decanted from the lower sulfuric acid layer and neutralized with a 30% aqueous solution of sodium hydroxide to a pH of approximately 7. Soditun sulfate is added to the resulting aqueous solution until the solids present in the resultant slurry contain a 60 to 40 Weight proportion of sodium sulfate to sodium tetradecyltoluene sulfonate. The slurry is thereafter evaporated to dryness and tested for detergency in a standard Launder-O-Meter apparatus, the product having a detergency rating of approximately 124 on the basis of sodium laurate as a standard of comparison having a rating of 100 by the same method of determination.

The detergent product comprising te-tradecyltoluene sulfonate prepared substantially in accordance with the above procedure except that a tetradecylene fraction in which the components are of mixed structure, including mono-, di-, triand tetra-alkyl ethylenes, such as a C14 fraction separated from a thermally cracked gas-oil fraction was utilized in the alkylation of toluene, yielding a product having a detergent rating of only about 104 on the basis of sodium laurate being 100. Since the detergent products prepared under otherwise identical conditions differ from each other only in the structure of the long chain alkyl group attached to the tolyl nucleus, it is presumed that the higher level of detergency for the secondary alkylaryl sulfonate of this invention is due to differences in structure rather than to methods of preparation.

I claim as my invention:

1. A process for the production of an alkylaryl hydrocarbon having an alkyl substituent containing from about 9 to about 18 carbon atoms per substituent joined to the aryl nucleus through a secondary carbon atom of said alkyl substituent which comprises reacting an alkyl halide containing from about 7 to about 16 carbon atoms per molecule with ethylene to form a primary alkyl halide containing from about 9 to about 18 carbon atoms per molecule, and condensing said primary alkyl halide with an aromatic hydrocarbon containing a nuclearly displaceable hydrogen atom to form said alkylaryl hydrocarbon.

2. The process of claim 1 further characterized in that said aromatic hydrocarbon is a benzenoid hydrocarbon.

3. The process of claim 1 further characterized in that said aromatic hydrocarbon is benzene.

4. The process of claim 1 further characterized in that said aromatic hydrocarbon is toluene.

5. The process of claim 1 further characterized in that the first mentioned alkyl halide is formed by reacting a propylene polymer containing from about 9 to about 12 carbon atoms per molecule with a hydrogen halide selected from the group consisting of hydrogen chloride and hydrogen bromide.

6. The process of claim 5 further characterized in that said propylene polymer fraction boils from about to about 225 C.

7. The process of claim 1 further characterized in that the first mentioned alkyl halide is formed by reacting a thermally cracked gas oil fraction boiling from about 170 to about 225 C. with a hydrogen halide selected from hydrogen chloride and hydrogen bromide.

References Cited in the file of this patent UNITED STATES PATENTS 2,477,382 Lewis July 26, 1949 2,495,323 Gislon Jan. 24, 1950 2,533,517 Schwoegler Dec. 12, 1950 OTHER REFERENCES Schmerling: Jour. Amer. Chem. Soc., vol. 67, pgs. ll521154, July 1945. 

1. A PROCESS FOR THE PRODUCTION OF AN ALKYLARYL HYDROCARBON HAVING AN ALKYL SUBSTITUENT CONTAINING FROM ABOUT 9 TO ABOUT 18 CARBON ATOMS PER SUBSTITUENT JOINED TO THE ARYL NUCLEUS THROUGH A SECONDARY CARBON ATOM OF SAID ALKYL SUBSTITUENT WHICH COMPRISES REACTING AN ALKYL HALIDE CONTAINING FROM ABOUT 7 TO ABOUT 16 CARBON ATOMS PER MOLECULE WITH ETHYLENE TO FORM A PRIMARY ALKYL HALIDE CONTAINING FROM ABOUT 9 TO 18 CARBON ATOMS PER MOLECULE, AND CONDENSING SAID PRIMARY ALKYL HALIDE WITH AN AROMATIC HYDROCARBON CONTAINING A NUCLEARLY DISPLACEABLE HYDROGEN ATOM TO FORM SAID ALKYLARYL HYDROCARBON. 